nanog mailing list archives

Re: ICMP Attacks???????


From: "Jay R. Ashworth" <jra () scfn thpl lib fl us>
Date: Fri, 22 Aug 1997 18:09:21 -0400

On Fri, Aug 22, 1997 at 02:42:42PM -0700, Joe Rhett wrote:
I don't think that's a good idea.  The vast majority of routers that
I sell to customers are not used in Internet applications, and to add
another configuration step to enable the router to do what routers
traditionally do by default would be very confusing to the end user.
 
You're saying that Corporate America *relies* on being able to to
IP source address spoofing through the routers it builds its commercial
private networks with?
 
<sigh> No, I believe he's saying that corporate america comes in two
flavors.

1) that isn't terribly clueful, and don't know how their packets route
(scary how often you see this .. RIP-based networks that "just work")

2) Multi-path, decentralized network administration. So any given router
will not be aware of all paths in the topology, and may route packets
that it doesn't know how to return. Deliberately.

Trust me, you don't know how your peer routes their traffic. Neither does
sales know how the engineering department does in some cases. Or the
backbone group knows all, and the department routers know nothing.

So far, so good.

In any case, this logic used for this would have to be very complex.
..which would cause complex problems. I prefer simple manual editing.

No, not really.

Actually, on the End-Of-Branch routers you could implement functions which
say not to route anything coming through a given interface unless it is
from that network. But this won't work on most branch router
configurations. 

This was what I originally proposed, in the posting from which this
thread descended.  Did everyone miss it?

Cheers,
-- jra
-- 
Jay R. Ashworth                                                jra () baylink com
Member of the Technical Staff             Unsolicited Commercial Emailers Sued
The Suncoast Freenet      "People propose, science studies, technology
Tampa Bay, Florida          conforms."  -- Dr. Don Norman      +1 813 790 7592


Current thread: